In the process industry and, in particular, in the biomass process industry such as in pulp manufacturing and in the manufacturing of bio fuels, discharge valves are used to control the pressure and/or process flow in process elements such as boilers, reactors and refiners which have inner pressurized process chambers. Shutter valves, gate valves and ball sector valves are the most commonly used types of discharge valves in the pulp manufacturing industry. The process flows in a process involving processing of lignocellulosic materials are generally corrosive, of a high temperature and with a high content of abrasive particulate material such as cellulose fibers and fragments and impurities following with the processed material. Consequently, a discharge valve being continuously exposed to a pressurized flow of hot, abrasive and corrosive material will wear out over time and will have to be replaced by a new valve. This is costly and, in addition, involves lengthy stop-times in the process as the process will have to be interrupted while the process equipment cools down and is cleaned so that the worn-down discharge valve can be disconnected from all couplings and a new discharge valve can be mounted in the place of the discarded valve.
It is therefore an object of the invention to provide a discharge valve having a more robust construction and longer service life. A further object of the invention may be to reduce process stop-times caused by valve maintenance. Yet another object may be to offer a discharge valve having greater versatility than previously used discharge valves.